Hemodynamics and Physics

Question 1

propagation velocity =

Answer 1

time

**the amount of TIME it takes US to travel 1cm into tissue and 1cm back to the transducer. therefore the signal obtained at 13microseconds is from 1cm deep

REMEMBER 13 MICROSECONDS!!!!!

Question 2

continuous wave (CW) doppler

Answer 2

has 2 crystals
has no range or depth resolution
does not alias

Question 3

fast Fourier transfer (FFT)

Answer 3

displays all the frequencies
digital spectral analysis (digital think DETAIL - displays all the frequencies)
commonly used in duplex exams

Question 4

pulsed wave (PW) doppler

Answer 4

single crystal
pulsed doppler has range of depth resolution

Question 5

pulse repetition frequency (PRF)

Answer 5

the number of pulses per unit of time sent into the tissue

Question 6

color doppler displays

Answer 6

mean frequency

Question 7

color bar displays

Answer 7

the flow diction RELATIVE to the transducer

Question 8

frequency

Answer 8

number of cycles (vibrations) per second

Question 9

requirements for angle of incidence
gray scale imaging =
doppler =

Answer 9

GS = 90 degrees is optimal
Doppler = 60 degrees or less

Question 10

what is the nyquist limit

Answer 10

doppler shifted frequency that is greater than 1/2 the PRF